JP2014190873A - Method for sampling impurity metal and method for analyzing metal component in solution - Google Patents

Abstract

An object of the present invention is to provide an impurity metal sampling method capable of sampling an impurity metal contained in a sample solution in a short time and with high accuracy while suppressing damage to a sampling device.
The method includes a step of evaporating a liquid 14A by heating a sample solution 14 in the collection container 13 under atmospheric pressure and recovering a residue containing an impurity metal 14B in the collection container 13; In the step of collecting the sample solution, a clean gas is blown from the outlet 15A located in the collection container 13 toward the liquid surface 14a of the sample solution 14, and the sample solution is collected from the collection port 28A disposed in the collection container 13. A gas containing 14 vapors is led out of the collection container 13.
[Selection] Figure 1

Description

  The present invention relates to sampling of an analyte contained in a sample solution such as a solution or a liquid material gas, and in particular, a method for sampling an impurity metal used when collecting an impurity metal contained in the sample solution, and the solution The present invention relates to a method for analyzing medium metal components.

  In recent years, semiconductor manufacturing plants manufacture semiconductors using liquid materials, for example, organic liquid materials such as TEOS, in the manufacturing process. In actual production, in order to confirm that the quality of the liquid material is stable, the components to be analyzed, for example, metal impurities in the material are regularly measured, and the amount satisfies the required quality. It is necessary to confirm that.

  As a quantitative analysis method for impurities in a liquid material, first, a liquid sample is evaporated to dryness using a hot plate or the like with an explosion-proof structure, the component to be analyzed (metal impurity) is sampled, and this is dissolved in a solvent. A method of measuring by ICP-MS or the like is known.

  However, in the above-described method, it takes a long time to evaporate and dry the liquid sample, and there is a possibility that contaminants derived from the environment may be mixed from the outside. Therefore, accurate quantification of metal impurities may be difficult.

  In view of this, a technique has been proposed that lowers the boiling point of the solution by reducing the pressure around the sample solution to improve the evaporation efficiency. For example, Patent Document 1 discloses an evaluation solution in a semiconductor substrate or chemical impurity analysis method in which an evaluation solution consisting of an acid or alkaline solution containing dissolved impurities to be inspected is analyzed by ICP-MS to specify the amount of impurities. Impurity analysis of semiconductor substrates or chemicals, including a step of concentrating or drying under reduced pressure without heating, a step of dissolving the residue with a hydrofluoric acid or hydrochloric acid solution to form a reevaluation solution, and a step of analyzing the reevaluation solution A method is disclosed.

JP 2001-242052 A

  However, when an object to be analyzed (for example, an impurity metal) in a solution is collected (sampled) using the method disclosed in Patent Document 1, equipment for maintaining a reduced pressure state and its management are required. There is an inconvenience.

  Also, for example, in the case where the evaporated solution is pumped using the vapor pressure generated when the solution constituting the sample solution is evaporated, if the temperature drops in the portion located in the subsequent stage, the evaporated solution is reliquefied. As a result, the stainless steel piping portion and the like are locally corroded.

  Furthermore, since the re-liquefied solution flows back into the container collecting the analyte, a contamination source derived from the impurity sampling device is taken in, so that the analyte contained in the sample solution is accurate. It was difficult to sample well.

  Therefore, the present invention provides a method for sampling an impurity metal capable of sampling an impurity metal contained in a sample solution in a short time and with high accuracy, and a method for analyzing a metal component in the solution, while suppressing damage to the impurity sampling device. The purpose is to provide.

  In order to solve the above-mentioned problem, according to the invention according to claim 1, a step of enclosing a sample solution containing a metal-containing liquid in a collection container having at least an inner surface made of a fluororesin, and under atmospheric pressure In the step of recovering the residue, the step of recovering the residue containing the metal in the collection vessel by evaporating the liquid by heating the sample solution in the collection vessel A clean gas is blown toward the liquid surface of the sample solution from a blowout port located inside, and a gas containing vapor of the sample solution is discharged from the collection port arranged in the collection vessel to the outside of the collection vessel. An impurity metal sampling method is provided.

  Moreover, according to the invention which concerns on Claim 2, the flow velocity of the said clean gas blown from the said blower outlet shall be in the range of 0.20-0.50 cm / sec. A method for sampling impurity metals is provided.

  According to the invention of claim 3, in the step of recovering the residue in the collection container, the liquid that evaporates is diluted with the clean gas, and the diluted liquid is exhausted, 3. The impurity metal sampling method according to claim 1, wherein the residue is collected.

  Moreover, according to the invention which concerns on Claim 4, the solution or liquid material gas whose boiling point is 200 degrees C or less is used as said liquid, The impurity metal of any one of Claim 1 thru | or 3 characterized by the above-mentioned. A sampling method is provided.

  Moreover, according to the invention which concerns on Claim 5, including the process of analyzing the said metal contained in the said residue collected by the sampling method of the impurity metal of any one of Claims 1 thru | or 4 A method for analyzing metal components in solution is provided.

  According to the impurity metal sampling method of the present invention, a step of enclosing a sample solution containing a metal-containing liquid in a collection container having at least an inner surface made of a fluororesin, and the inside of the collection container under atmospheric pressure The sample solution is heated to evaporate the liquid and the residue in the collection container is collected. In the step of collecting the residue, the sample solution is moved from the outlet located in the collection container to the liquid level of the sample solution. When the liquid is highly reactive by blowing a clean gas toward it and letting the gas containing the sample solution vapor out of the collection container through the collection port arranged in the collection container However, it is possible to sample the impurity metal contained in the sample solution in a short time and with high accuracy while suppressing damage to the collection container and the pipe constituting the impurity sampling device.

1 is a system diagram showing a schematic configuration of an impurity sampling device used when performing an impurity metal sampling method according to an embodiment of the present invention, and among components of the impurity sampling device, a configuration arranged in a clean booth It is the figure which showed the element in the cross section. It is sectional drawing to which the part enclosed by the area | region A of the impurity sampling apparatus shown in FIG. 1 was expanded, and the figure which illustrated only the collection container, the gas supply line, and the liquid exhaust line among the components of the impurity sampling apparatus. is there. It is a figure which shows the time required for the sampling of the to-be-analyzed component contained in the 1st thru | or 3rd sample. It is a figure which shows the recovery rate of the to-be-analyzed component contained in the 1st and 3rd sample, (a) is the recovery rate of the to-be-analyzed component by the method of an Example, (b) is to be analyzed by the method of the comparative example 1. The component recovery rate, (c), shows the recovery rate of the component to be analyzed by the method of Comparative Example 2, respectively. It is a figure which shows the relationship between the flow rate of nitrogen, and the time which sampling of the impurity metal contained in a 1st sample requires.

  Embodiments to which the present invention is applied will be described below in detail with reference to the drawings. The drawings used in the following description are for explaining the configuration of the embodiment of the present invention, and the size, thickness, dimension, etc. of each part shown in the drawings are different from the dimensional relationship of an actual sampling device. There is.

(Embodiment)
FIG. 1 is a system diagram showing a schematic configuration of a sampling device used when carrying out a method for sampling an impurity metal according to an embodiment of the present invention, and is arranged in a clean booth among components of the sampling device. FIG.
FIG. 2 is an enlarged cross-sectional view of a portion surrounded by the region A of the sampling device shown in FIG. 1, and shows only the collection container, the gas supply line, and the liquid exhaust line among the components of the sampling device. FIG.

First, with reference to FIG. 1 and FIG. 2, the sampling apparatus 10 used when implementing the impurity metal sampling method which concerns on embodiment of this invention is demonstrated.
The sampling device 10 includes a clean booth 11, a collection container 13, a gas supply line 15, a sintering filter 17, a pressure reducing valve 18, a stop valve 19, a line heater 22, and a metal container 24. , A container heater 26, a liquid exhaust line 28, a cooling trap 31, and a flow meter 33.

  The clean booth 11 is for keeping the atmosphere in the clean booth 11 clean compared to the atmosphere outside the clean booth 11 (a state where there is little dust). The clean booth 11 leads a through hole (not shown) for guiding the gas supply line 15 from the outside of the clean booth 11 into the clean booth 11 and a liquid exhaust line 28 from the outside of the clean booth 11 into the clean booth 11. And a through hole (not shown).

  The collection container 13 has a container body 13A and a lid body 13B. In the container main body 13A, a sample solution 14 containing a liquid 14A containing an impurity metal 14B (metal) that is an object to be analyzed is accommodated. The pressure in the collection container 13 is atmospheric pressure.

  Examples of the liquid 14A include a solution having a boiling point of 200 ° C. or lower (for example, water) or a liquid material gas. Examples of the liquid material gas having a boiling point of 200 ° C. or lower include tetraethoxysilane (TEOS), tetrakisdimethylaminosilane (4DMAS), bistetrabutylaminosilane (BTBAS), dimethylsulfoxide (DMSO), water, and the like. .

  The lid body 13 </ b> B has a first through hole 36 for allowing the gas supply line 15 to pass therethrough and a second through hole 37 for allowing the recovery port 28 </ b> A of the liquid exhaust line 28 to pass therethrough. The lid 13B is attached to the upper end of the container body 13A.

  As the collection container 13 having the above-described configuration, for example, a container in which a fluorine-based resin excellent in heat resistance, chemical resistance, and flame retardancy is used on at least an inner surface in contact with the sample solution 14 and its vapor is used. Good. As the fluororesin, for example, polytetrafluoroethylene (PTFE) having a heat resistance of about 260 ° C., polytetrafluoroethylene (PFA) and the like are preferable.

  In this way, by using the sample solution 14 containing the liquid 14A containing the impurity metal 14B and the collection container 13 using the fluorine-based resin on the inner surface where the vapor contacts, the liquid 14A can be captured even when it has high reactivity. It is possible to suppress the collection container 13 from reacting with the liquid 14A. Thereby, it is possible to suppress the collection container 13 from being deformed or damaged by the liquid 14A.

  The gas supply line 15 is connected to a gas supply source (not shown) and has a blowout port 15A for blowing the gas supplied from the gas supply source (not shown).

The gas supply line 15 extends from the outside of the clean booth 11 into the clean booth 11 through a through hole (not shown) provided in the clean booth 11, and includes a lid body 26 </ b> B of the container heater 26, and It extends into the collection container 13 through the through hole 36 of the lid 13B.
The blowout port 15 </ b> A is arranged so that the gas blowout direction is perpendicular to the liquid surface of the sample solution 14. Thereby, evaporation of the sample solution 14 arrange | positioned in the collection container 13 can be accelerated | stimulated.

Gas supplied from a gas supply source (not shown) (for example, inert gas such as nitrogen, rare gas elements such as helium, neon, and argon) passes through the sintered filter 17 and becomes clean gas. Thereafter, the liquid is sprayed onto the liquid surface 14 a of the sample solution 14 through the air outlet 15 A of the gas supply line 15.
In the present invention, “clean gas” refers to a gas having a smaller amount of component to be analyzed than the atmosphere. As the clean gas, for example, an inert gas that has passed through a filter can be used.

The distance D between the blowout port 15A and the liquid surface 14a of the sample solution 14 is preferably set to 10 mm or more, and the flow rate of clean gas blown out from the blowout port 15A is set within a range of 0.20 to 0.50 cm / sec. .
Under such conditions, by blowing clean gas to the liquid surface 14a of the sample solution 14 through the blowout port 15A, the sample solution 14 can be convected, and bumping of the sample solution 14 can be suppressed. The vapor 14A can be discharged out of the collection container 13 along with clean gas.

The sintered filter 17 is provided in the gas supply line 15 located outside the clean booth 11. The sintered filter 17 is a filter for obtaining a gas cleaner than the outside air by removing impurities contained in a gas supplied from a gas supply source (not shown).
As described above, by using the sintered filter 17 as a filter for removing impurities contained in the gas, a cleaner gas can be obtained as compared with the case where a wire mesh filter is used.

Thereby, since it becomes possible to suppress the impurity (specifically, impurity metal) contained in the gas from entering the collection container 13, it is possible to collect only the impurity metal 14B with high accuracy.
As the sintered filter 17, for example, a sintered filter made of SUS (stainless steel) can be used.

  The pressure reducing valve 18 is provided in the gas supply line 15 located between the clean booth 11 and the sintered filter 17. The pressure reducing valve 19 maintains the pressure of the gas at a constant pressure by reducing the pressure of the clean gas.

The stop valve 19 is provided in the gas supply line 15 located between the clean booth 11 and the pressure reducing valve 18.
The stop valve 19 is a valve that adjusts the flow rate of clean gas supplied to the gas supply line 15 located in the clean booth 11 by stopping the flow of clean gas or adjusting the opening of the valve. is there.
Thus, by providing the stop valve 19 in the gas supply line 15, the flow rate of the clean gas blown out from the blowout port 15A is set to a desired flow rate (specifically, 0.20 to 0.50 cm / sec). Can be adjusted within range.

  The line heater 22 is provided in a portion of the gas supply line 15 located in the clean booth 11 and located outside the lid body 26B. The line heater 22 is a heater for heating clean gas flowing through the gas supply line 15 at a temperature lower than the boiling point of the liquid 14A.

When the boiling point of the liquid 14 </ b> A is 200 ° C., the line heater 22 heats the clean gas so that the clean gas has a temperature in the range of 80 to 150 ° C., for example.
Thus, when the boiling point of the liquid 14A is 200 ° C., the line heater 22 heats the clean gas so that the temperature of the clean gas is in the range of 80 to 150 ° C. When stopped, the temperature difference (in this case, 20 to 50 ° C.) from the boiling point of the liquid 14 </ b> A can prevent the clean gas from flowing back to the gas supply line 15.

As described above, when the clean gas is sprayed into the collection container 13 by having the line heater 22 for heating the clean gas before being sprayed to the sample solution 14 accommodated in the collection container 13. It is possible to suppress a decrease in the temperature in the collection container 13 and the temperature of clean gas.
Thereby, when the sampling method of the impurity metal according to the embodiment is performed using the sampling device 10, the sampling of the impurity metal (in a shorter time than when the clean gas is sprayed on the liquid surface 14a without heating) (Capture) can be terminated. As the line heater 22, for example, a mantle heater can be used.

  The metal container 24 is provided so as to cover the outer surface of the container body 13A. In other words, the metal container 24 accommodates the container main body 13A so as to contact the outer surface of the container main body 13A. The metal container 24 is a container for suppressing a decrease in the temperature of the collection container 13. As a material of the metal container 24, for example, aluminum can be used.

The container heater 26 includes a first portion 26A and a second portion 26B. The first portion 26 </ b> A is disposed so as to cover the outer surface of the metal container 24. The second portion 26B is disposed so as to cover a part of the outer surface of the container main body 13A and the lid body 13B.
The container heater 26 heats the sample solution 14 so as to reach the boiling point of the liquid 14A accommodated in the container body 13A via the metal container 24, a part of the outer surface of the container body 13A, and the lid body 13B. To do.

The liquid exhaust line 28 is connected to an abatement apparatus (not shown) and has a recovery port 28A for recovering the liquid 14A.
The liquid exhaust line 28 extends from the outside of the clean booth 11 into the clean booth 11 through a through hole (not shown) provided in the clean booth 11, and includes a lid body 26 </ b> B of the container heater 26, and The collection port 28 </ b> A is arranged in the collection container 13 by extending into the collection container 13 through the through hole 37 of the lid 13 </ b> B.

The collection port 28A is disposed above the blowout port 15A. The liquid exhaust line 28 collects the evaporated liquid 14A entrained in the clean gas from the outlet 15A, and then passes through the cooling trap 31 and the flow meter 33, and then removes the liquid 14A diluted with the clean gas. Supply to a device (not shown).
Thus, by diluting the liquid 14A using a clean gas, the liquid 14A can be safely supplied to the abatement device (not shown) even when the liquid 14A has toxicity.

Examples of the material of the liquid exhaust line 28 configured as described above include a fluorine-based resin (for example, polytetrafluoroethylene (PTFE) having a heat resistance of about 260 ° C. or the like having excellent heat resistance, chemical resistance, and flame retardancy). , Polytetrafluoroethylene (PFA), etc.) may be used.
Thus, by using a fluorine-based resin as the material of the liquid exhaust line 28, it is possible to suppress the liquid exhaust line 28 from reacting with the liquid 14A even when the liquid 14A included in the sample solution 14 has high reactivity. .

  The cooling trap 31 is provided in the liquid exhaust line 28 located outside the clean booth 11. The cooling trap 31 collects harmful liquid transported by the liquid exhaust line 28, thereby preventing damage to equipment provided in the subsequent stage such as a suction pump (not shown) due to the harmful liquid. It has a function.

  The flow meter 33 is provided in the liquid exhaust line 28 located between the abatement apparatus (not shown) and the cooling trap 31. The flow meter 33 measures the flow velocity of the fluid flowing through the liquid exhaust line 28.

Next, the impurity metal sampling method of the present embodiment using the sampling apparatus 10 described above will be described with reference to FIGS.
First, in the clean booth 11, a sample containing a liquid 14A containing an impurity metal 14B (metal), which is an object to be analyzed, in a collection container 13 that is at atmospheric pressure and has at least an inner surface made of a fluororesin. The solution 14 is enclosed.
Thereafter, the lid 13B provided with the second portion 26B (a part of the container heater 26) is closed. At this time, the distance D between the liquid level 14a and the outlet 15A is set to be 10 mm or more.

Next, by heating the sample solution 14 in the collection container 13 under atmospheric pressure, the liquid 14A is evaporated, and the residue containing the impurity metal 14B in the collection container 13 is collected (step of collecting the residue).
In the step of collecting the residue, clean gas is blown from the blowing port 15A located in the collection container 13 toward the liquid surface 14a of the sample solution 14, and from the collection port 28A disposed in the collection container 13. A gas containing vapor of the sample solution 14 is led out of the collection container 13.
At this time, the liquid 14A to be evaporated is diluted with a clean gas, and the residue is collected while exhausting the diluted liquid 14A.

Specifically, a step of collecting the residue is performed by the following method.
First, the power supply of the line heater 22 is turned on, and the gas supply line 15 is heated so that the temperature of the clean gas flowing in the gas supply line 15 is in the range of 80 to 150 ° C.
Next, a gas (for example, inert gas) supplied from a gas supply source (not shown) is transported through the gas supply line 15 and passed through the sintered filter 17. Thereby, impurities (including metal) contained in the gas are removed, and a gas that is cleaner than the outside air (air outside the clean booth 11) is supplied to the stop valve 19.

Next, by adjusting the opening degree of the stop valve 19, the gas supply amount (in other words, the flow rate of the clean gas supplied from the outlet 15A is adjusted).
Specifically, the flow rate of the clean gas blown from the blowout port 15A to the liquid surface 14a is adjusted to be in the range of 0.20 to 0.50 cm / sec. Further, the pressure of the clean gas is adjusted by the pressure reducing valve 18 so as to become a predetermined pressure.

As a result, clean gas having a predetermined pressure and a predetermined flow velocity is supplied to the gas supply line 15 located in the clean booth 11.
Next, the clean gas is heated by the line heater 22 at a temperature (for example, 80 to 150 ° C.) lower than the boiling point (for example, 200 ° C.) of the liquid 14A. Thereafter, clean gas is sprayed from the outlet 15A to the liquid surface 14a at a flow rate in the range of 0.20 to 0.50 cm / sec.

As a result, the sample solution 14 can be convected, so that the sample solution 14 can be prevented from bumping and the liquid 14A evaporated out of the collection container 13 can be purified gas via the liquid exhaust line 28. Can be accompanied with.
Thereby, the impurity metal 14 </ b> B contained in the liquid 14 can be accurately left in the collection container 13.

  The sample solution 14 transported by the liquid exhaust line 28 collects harmful liquid by the cooling trap 31, and the remainder is supplied to the abatement device (not shown) via the flow meter 33. It is processed.

  According to the impurity metal sampling method of the present embodiment, the step of enclosing the sample solution 14 containing the liquid 14A containing the impurity metal 14B in the collection container 13 of which at least the inner surface is made of a fluororesin, and the atmospheric pressure The sample solution 14 in the collection container 13 is heated to evaporate the liquid 14A and recover the residue in the collection container 13. In the process of recovering the residue, A clean gas is blown from the positioned outlet 15A toward the liquid surface 14a of the sample solution 14, and gas containing the vapor of the sample solution 14 is collected from the collection port 28A disposed in the collection container 13 into the collection container 13. When the liquid 14A is highly reactive, the loss of the collection container 13 and the liquid exhaust line 28 constituting the sampling device 10 can be reduced. The on while suppressing a short and can be sampled impurity metal 14B contained in precisely the sample solution 14.

  Further, the residue containing the impurity metal 14B collected by the sampling method described above is dissolved in, for example, a hydrochloric acid solution or a hydrofluoric acid solution, and the solution is introduced into an analyzer such as ICP-MS, whereby the sample solution 14 Impurity metal 14B can be analyzed accurately and quickly.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

(Evaluation test)
Hereinafter, in order to confirm the effectiveness of the sampling method of the present invention, an experiment in which the metal component (impurity metal 14B) in various liquid materials is quantified will be described.
First, tetraethoxysilicon (TEOS, boiling point 168.8 ° C.) was prepared as the first liquid, water as the second liquid, and dimethyl sulfoxide (DMSO, boiling point 189 ° C.) as the third liquid.
In addition, a multi-element mixed standard solution (model number: XSTC-622) manufactured by SPEX was prepared as a standard solution in which traceability was ensured.

  Next, three commercially available fluororesin containers were prepared as the collection container 13. Next, 5 g of the first liquid is dispensed into the first fluororesin container, 5 g of the second liquid is dispensed into the second fluororesin container, and the third fluororesin container. 5 g of the third liquid was dispensed.

Next, the standard solution was diluted to prepare a diluted standard solution having a final adjusted concentration of 1 μg / L. Next, a diluted standard solution was added to each of the three fluororesin containers (first to third fluororesin containers) as a specimen for addition recovery test.
Accordingly, the first sample (sample solution) composed of the first liquid and the diluted standard solution, the second sample (sample solution) composed of the second liquid and the diluted standard solution, the third liquid and the diluted standard solution. A third sample (sample solution) made of the solution was prepared.

Next, using the sampling device 10 shown in FIG. 1, a fluororesin liquid exhaust line 28 is attached to each fluororesin container, and nitrogen, which is a cleaner gas than the outside air, is supplied to the surface of each sample from the blowout port 15A. When (N ₂ ) is blown (in this case, the flow rate of nitrogen blown from the blowout port 15A is 0.30 cm / sec), and when nitrogen is not blown (when released to the atmosphere at a safe sampling point (draft)) ) And when bubbling nitrogen in each sample (in this case, the flow rate of nitrogen was 0.3 cm / sec).
At this time, the distance between the liquid level of each sample and the outlet 15A was 10 mm.

Hereinafter, an experiment with a method of blowing nitrogen (N ₂ ), which is a gas cleaner than the outside air, is referred to as an example, and an experiment with a method of not blowing nitrogen is referred to as comparative example 1, and a method of bubbling nitrogen to each sample. This experiment is referred to as Comparative Example 2.

At this time, a ribbon heater is used as the line heater 22, and the temperature (specifically, 80 to 150) lower than the boiling point of the liquid (any one of the first to third liquids) contained in each sample. The nitrogen was heated within the range of ° C.
In addition, a mantle heater was used as the container heater 26, and the mantle heater was used to heat the collection container 13 so that the temperature of the liquid contained in each sample became the boiling point of the liquid.

Then, after the sampling process was completed, the metal residue remaining in each fluororesin container was collected. FIG. 3 shows data relating to the time required for the sampling process at this time.
FIG. 3 is a diagram showing the time required for sampling the components to be analyzed contained in the first to third samples.

Next, using a hydrochloric acid (HCl) solution having a concentration of 0.5%, the metal residue collected from each fluorine resin container was eluted.
Next, the hydrochloric acid solution eluting the metal residue was introduced into 7500cs, which is a high frequency inductively coupled plasma mass spectrometer (ICP-MS) manufactured by Agilent Technologies, and the components to be analyzed (specifically, Na, Fe, Cu, Ca, Ni, Zn) was quantified.
The recovery rate was measured only for the first sample and the third sample.

  The result is shown in FIG. FIG. 4 is a diagram showing the recovery rates of the analytes contained in the first and third samples, (a) is the recovery rate of the analytes by the method of the example, and (b) is the comparative example 1. The recovery rate of the component to be analyzed by the method and (c) show the recovery rate of the component to be analyzed by the method of Comparative Example 2, respectively.

Moreover, the time required for sampling of the component to be analyzed was measured by changing the flow rate of nitrogen within the range of 0.1 to 1.0 cm / sec using the first sample. The result is shown in FIG.
FIG. 5 is a diagram showing the relationship between the flow rate of nitrogen and the time required for sampling the component to be analyzed contained in the first sample.

(Evaluation test results)
Referring to FIG. 3, it was found that in Example and Comparative Example 2, the liquid evaporates in a shorter time than Comparative Example 1, and the sampling process for the component to be analyzed is completed in a shorter time.
Referring to FIG. 4A, in the example, the recovery rate was close to 100% regardless of which of the first and third samples was used, and good results were obtained.

On the other hand, referring to FIG. 4 (c), in Comparative Example 2, the recovery rate was considerably smaller than 100% in any of the first and third samples.
As described above, the reason why the recovery rate of Comparative Example 2 was considerably smaller than 100% was that when the gas was passed through the first and third samples, the samples splashed and were originally made of a fluororesin. It is considered that the impurity metal that should have remained in the container was entrained outside the fluororesin container together with the ventilation gas.

Further, referring to FIG. 4B, in Comparative Example 1, the recovery rate of components to be analyzed such as Na and Ca was a high value. In the case of opening to the atmosphere, this may be due to contamination from the outside.
From the result shown in FIG. 4 described above, by using the method of the embodiment to which the present invention is applied, the liquid contained in the sample (sample solution) evaporates at an early stage, and the sampling process of the component to be analyzed contained in the sample is performed. It was possible to carry out easily, and it was confirmed that the analysis result obtained from the analyzer was also highly accurate.

  Referring to FIG. 5, if the flow rate of nitrogen blown from the blowout port 15A is increased, the time required for sampling the analyte contained in the sample is shortened, but the flow rate of nitrogen is 0.6 cm / sec or more. As a result, it was found that the time required for the sampling process of the component to be analyzed becomes longer.

This is because when the flow rate of nitrogen is low (less than 0.6 cm / sec), the nitrogen heater is effectively heated by the ribbon heater, and the nitrogen gas heated to a desired temperature is efficiently used. It is thought that it was because it was sprayed on the surface.
However, when the flow rate of nitrogen is 0.1 cm / sec or less, it is considered that the effect of spraying nitrogen on the liquid surface of the sample is considerably reduced, and as a result, the time required for collecting the components to be analyzed is increased.

  Therefore, from the result shown in FIG. 5 described above, when the time required for sampling the analyte is within 60 minutes, the flow rate of nitrogen blown from the outlet to the liquid surface of the sample is 0.20 to 0.50 cm / It was confirmed that a value within the range of sec was preferable.

  The present invention can be applied to an impurity metal sampling method capable of sampling an impurity metal contained in a sample solution in a short time and with high accuracy while suppressing damage to the impurity sampling device.

  DESCRIPTION OF SYMBOLS 10 ... Sampling apparatus, 11 ... Clean booth, 13 ... Collection container, 13A ... Container main body, 13B ... Cover body, 14 ... Sample solution, 14a ... Liquid surface, 14A ... Liquid, 14B ... Impurity metal, 15 ... Gas supply line 15A ... Blowout port, 17 ... Sintering filter, 18 ... Pressure reducing valve, 19 ... Stop valve, 22 ... Line heater, 24 ... Metal container, 26 ... Vessel heater, 26A ... First part, 26B ... No. 2 part, 28 ... liquid exhaust line, 28A ... recovery port, 31 ... cooling trap, 33 ... flow meter, 36, 37 ... through hole, D ... distance

Claims (5)

Enclosing a sample solution containing a metal-containing liquid in a collection container having at least an inner surface made of a fluororesin;
Heating the sample solution in the collection container under atmospheric pressure to evaporate the liquid and recovering the metal-containing residue in the collection container;
In the step of recovering the residue, a clean gas is blown toward the liquid surface of the sample solution from a blowout port located in the collection container, and the sample solution is discharged from a collection port provided in the collection container. A method for sampling an impurity metal, wherein a gas containing vapor is led out of the collection container.   2. The impurity metal sampling method according to claim 1, wherein a flow rate of the clean gas blown out from the blow-out port is in a range of 0.20 to 0.50 cm / sec.   2. The step of recovering the residue in the collection container, wherein the liquid is evaporated with the clean gas, and the residue is recovered while exhausting the diluted liquid. Or the impurity metal sampling method described in 2;   4. The impurity metal sampling method according to claim 1, wherein a solution having a boiling point of 200 ° C. or less or a liquid material gas is used as the liquid. 5.   A method for analyzing a metal component in a solution, comprising a step of analyzing the metal contained in the residue collected by the impurity metal sampling method according to any one of claims 1 to 4.

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